This invention relates to a processing method and a processing apparatus for use in the manufacture of semiconductor devices. In particular, it relates to a processing method and a processing apparatus which can be used for the cleaning or gettering of a semiconductor wafer.
During the manufacture of semiconductor devices, it is necessary to clean semiconductor wafers. This cleaning is usually carried out using a cleaning apparatus of the type which is schematically illustrated in FIG. 1. As shown in this figure, a rotating brush B slides over the surface of a semiconductor wafer W in the direction of arrow T while being rotated about its axis in the direction shown by arrow R. At the same time, ultrapure water is sprayed at the surface of the wafter W by a jet nozzle N.
In this conventional method, it is difficult to remove ultrafine contaminant particles having a diameter on the order of 10 microns or less. In addition, due to the friction between the brush B and the wafer W, the brush B becomes worn and particles of the brush B adhere to the surface of the wafer W. Therefore, the brush B itself becomes a source of contamination. Furthermore, the friction between the brush B and the surface of the wafer W generates static electricity, which causes contaminants to adhere to the wafer surface and reduces the effectiveness of cleaning. There is thus a need for a cleaning method which can remove ultrafine contaminant particles without producing further contamination or static electricity.
Conventional gettering methods for semiconductor wafers suffer from similar problems. Extrinsic gettering of a semiconductor wafer can be performed by a wide variety of methods. One method is to blast particles of silica at the back side of a semiconductor wafer, thereby forming a damaged layer containing lattice defects. Another method is to produce a damaged layer using a quartz brush. However, in the blasting method using silica particles, the particles tend to adhere to the back side of the wafer and contaminate the wafer during subsequent manufacturing steps. In the method using a quartz brush, particles of the brush are worn by contact with the wafer. The worn brush particles also tend to adhere to the wafer and contaminate it.